With the rapid development of LED technologies, the LED gradually becomes a preferred new green lighting because of its advantages, such as, energy-saving, environmental protection, etc. Since incandescent and electronic energy-saving lamps still occupy a very high proportion in daily use, in order to reduce waste and use the existing interfaces, an LED light bulb using the existing interfaces was developed, for which traditional lamp base and circuit do not need to be changed. With regard to the LED light bulb for indoor lighting, the basic requirements on its luminous intensity distribution and luminance include that the light-emitting of the lamp should be omnidirectional, the luminous intensity distribution should be as uniform as possible, and the luminous flux of areas above and below the bulb should reach a set value to avoid the unevenness of light and shade which may make the user feel depressed. The suggested luminous intensity value is 100-300 cd/m2 in the operating region, 100-300 cd/m2 on the ceiling, and 50-150 cd/m2 on the wall surface. In order to regulate the production of LED light bulb, ENERGY STAR issued a new standard of LED lighting at the end of 2009, which prescribes the luminous intensity distribution of omnidirectional LED lamp (also called as non-directional lamp). It is prescribed in the standard that products shall have an even distribution of luminous intensity (candelas) within the 0° to 135° zone (vertically axially symmetrical). Luminous intensity at any angle within this zone shall not differ from the mean luminous intensity for the entire 0° to 135° zone by more than 20%. At least 5% of total flux (lumens) must be emitted in the 135° to 180° zone. That is to say, in the zone within 270 degrees below the bulb, the luminous intensity should be large and even, and in the zone within 90 degrees above the bulb, the luminous flux should not be too small.
As it is well known, because the LED light source is packaged, an angle formed by the luminous surface is 180 degree at maximum, and its half-intensity angle is generally 140 degree at maximum. For most of the currently-used LED light bulbs, a plane type LED integrated module light source is implanted in the bulb, but the luminous surface is narrow, thus omnidirectional light-emitting can not be realized. The Chinese Patent Application No. 200920206369.2 disclosed “a lamp bulb” which may realize large light-emitting angles. However, for its complicated structure and too many contact surfaces, it is difficult to be manufactured, and not suitable for mounting a chip with large power together with poor heat dissipating effect, and short service life. The Chinese Invention Patent Application No. 201010146167.0 disclosed “an LED bulb lamp capable of improving light transmittance”, wherein an LED module is fixed on an inclined plane. However, omnidirectional light-emitting of the LED bulb lamp can not be realized because the luminous flux of rear end of the bulb is lower even though the light angle is extended, and the LED bulb lamp also has disadvantages of complicated structure, difficult manufacture, unfavorable heat dissipating effect and short service life. There are other LED light bulbs adopting special lens to perform light distribution, namely that on the basis of the conventional LED lamp, an upward astigmatism lens is arranged on the surrounding LED. Although such LED light bulbs can meet the standard requirement on luminous intensity distribution, it easily brings a phenomenon of inconsistency of light color temperature and thus causes visual fatigue because of difference between light refractive indexes of different colors.